The electrically insulative properties of thermally stable plastic materials multi-functionally houses and insulates the electrical components contained therein for electrical switching applications. The impact resistance of the plastic material facilitates mounting the movable components within the plastic enclosure without fear of damage caused by the violent arcs that occur when the switch contacts are connected and disconnected while carrying current. Suitable plastic materials for the switch enclosure are "Valox", a registered trademark of GE Company for polybutylene terepthalate and "Noryl", a trademark of GE Company for a modified polyphenylene oxide. One such molded plastic enclosure for electrical disconnect switches is described within U.S. Pat. No. 4,675,782 which is incorporated herein for reference purposes.
It is understood that electric arcs will form between a pa1r of electric contacts when the current through the contacts is interrupted and some arc chute means are required to cool and quench the electric arc. The larger the current during interruption, the more intense the arc and hence, the larger the arc chute required. The duration of the arc is related to the time involved in moving the electric contacts a sufficient distance such that the arc voltage necessary to maintain the arc is greater than the available systems voltage.
An early attempt to rapidly make and break electrical connection between a pair of separable contacts is found in U.S. Pat. No. 4,233,482, wherein the movable contact carrier engage an over-center spring to rapidly accelerate the opening and closing forces applied during manual operation of the movable contact carrier.
U.S. Pat. No. 4,675,481 entitled "Compact Electric Safety Switch" describes a safety switch that rapidly connects and disconnects between a pair of contacts with minimum arc formation. This Patent is incorporated herein for purposes of reference and should be reviewed for its teachings of an operating handle that is rotated to drive a pair of powerful operating springs to effect rapid contact interaction. The use of a rotating operating handle is somewhat limited both with respect to space requirements as well as to the right-handedness and left-handedness of potential operators. A right-handed operator would favor the arrangement of the operating handle on the right hand side of the switch, for example, whereas the left-handed operator would prefer the operating handle to be arranged on the left side of the switch. This often requires extra mounting hardware to be inventoried by the switch manufacture.
A slidably-operated handle operator readily solves both the limited space as well as left-handedness, right-handedness preference problems. One such switch employing a slidably arranged handle operator is described within U.S. patent application Ser. No. 026,496 filed Mar. 16, 1987 entitled "Fused Disconnect Switch with Non-Metallic Enclosure", which Application is incorporated herein for purposes of reference.
One purpose of the instant invention is to provide an electric switch that can be readily fitted with either a slidably-operated handle operator or with a rotatable left hand or right hand operator with a minimum requirement of inventoried parts.